title: Natural history of acalculous biliary symptoms.
abstract: BACKGROUND
  The radiological criteria for the diagnosis of gallbladder disease rely largely on the detection of calculi using ultrasonography. Patients may, however, suffer symptoms typical of biliary pain without detectable gallstones. The aim of this study was to identify a cohort of patients presenting with recurrent episodes of biliary symptoms in the absence of identifiable pathology on ultrasonography and to record the outcome of subsequent imaging investigations.
  
  
  METHODS
  Records of patients having abdominal ultrasonography during a four-month period in 2006 were accessed retrospectively and those with symptoms suggesting biliary disease were identified. Radiology records were reviewed over a five-year follow-up period to identify patients undergoing further imaging for recurrent biliary symptoms and outcomes were recorded.
  
  
  RESULTS
  A total of 512 patients had ultrasonography for investigation of symptoms consistent with biliary disease. Almost half (41.2%) of these were found to have gallbladder pathology on ultrasonography and 4.7% of patients went on to have further investigations for similar symptoms without achieving a diagnosis. The median age of this group was 47 years and 75% of these patients were female. During the follow-up period, 2.6% of patients with biliary symptoms and initially normal ultrasonography developed gallstones and in 1.3% pancreatitis was demonstrated on imaging.
  
  
  CONCLUSIONS
  A small minority of patients who present with biliary symptoms and have no abnormality on ultrasonography present with recurrent symptoms or develop significant biliary pathology. These patients should be identified by interview at routine follow-up visits and further investigations should be considered.
authors.affiliation: Plymouth Hospitals NHS Trust, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: Warwick
authors.forename: F
authors.initials: F
authors.lastname: Bintcliffe
authors.forename: E
authors.initials: E
authors.lastname: Wu
authors.forename: D
authors.initials: D
authors.lastname: Stell
mesh_terms: D000328:Adult; D000368:Aged; D059350:Chronic Pain / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D005705:Gallbladder Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D042882:Gallstones / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000209:etiology; D012008:Recurrence; D012189:Retrospective Studies; D014463:Ultrasonography